1. Field of the Invention
The present invention relates to a linear vibration motor and, more particularly, to a linear vibration motor for vibrating a mass body in a horizontal direction within a mobile terminal and having a buffer member for the mass body.
2. Description of the Related Art
A vibration motor is a component for converting electric energy into mechanical vibrations by using the principle of the generation of electromagnetic force. The vibration motor, tending to become smaller and lighter, is employed in a mobile terminal to provide a mute (or silent) incoming call notification function or various vibration functions.
In particular, as mobile terminals have been reduced in size and have improved in quality, the use of a touch screen type LCD has been favored, requiring a function of generating vibrations when a touch is applied to the touch screen, so the improvement of the vibration motor has gradually taken place.
Recently, in order to implement a vibration function in touch screen phones, touch screen phones have employed a linear vibration motor. The linear vibration motor, rather than being based on the principle that a motor rotates, is excited by an electromagnetic force having a resonance frequency determined by using a spring installed within the linear vibration motor and a mass body hanging on the spring, to thereby generate vibrations.
Here, the electromagnetic force is generated by an interaction of a magnet positioned alongside the mass body in motion and a coil providing current of a certain frequency at a position corresponding to the magnet.
The linear vibration motor is configured to generate vibrations in a direction perpendicular to the LCD screen. However, in the case of vertical vibrations, a vertical displacement must be secured for the mass body to move to generate vibrations, resulting in a restriction in the thickness of the terminal.
Also, the reduction in the thickness of the terminal causes a problem in that the amount of vibrations produced by the vibration motor cannot be increased.